The present invention relates generally to exhaust systems of the type used for restaurant cooking equipment and more, particularly, to a reusable grease filter adapted to be used at an inlet portion of such an exhaust system.
In commercial cooking operations such as restaurants, the hot air and smoke produced by a cooking surface are conventionally removed by an exhaust system which includes a hood positioned above the cooking surface, an exhaust duct system associated with the hood, and a fan which draws air from beneath the hood and discharges it to the atmosphere outside the restaurant. Grease filters are positioned in the hood at the exhaust duct inlet to remove grease from the air before it enters the exhaust duct. Such filtering is necessary to retard the accumulation of grease in the exhaust system duct work and fan. In order to prevent any grease which does collect in the exhaust duct from being ignited by a fire in the cooking area, most modern day grease filters are adapted to retard the passage of flame therethrough. Conventional prior art grease filters, in order to accomplish both the function of collecting grease and preventing flame passage, have generally consisted of an intertwined wire mat which is sufficiently dense to restrict flame passage while being sufficiently porous to allow air passage. Such grease filters are generally inclined, on the order of 45.degree., so that grease collecting on the filter wire may flow downwardly and be collected in a grease trough and grease cup positioned at the base of the filter.
A problem with such prior art grease filters is that the intertwined wire surfaces do not lend themselves to rapid cleaning. In modern day restaurant operations, cooking equipment and the associated hood and exhaust system are periodically cleaned and degreased by specialized maintenance contractors who are generally not employees of the restaurant. The cleaning operation is generally performed in a relatively short time which is insufficient for the soaking, etc. that would be necessary for cleaning conventional grease filters. As a result, most modern day grease filters are disposable units which are replaced with each periodic cleaning operation. However, commercial grease filters are relatively expensive and represent a substantial portion of a restaurant's cost for this type of cleaning. It would be generally desirable to provide a grease filter having the equivalent or better grease removal and flame retarding characteristics as conventional grease filters but which is adapted for rapid cleansing and reuse.